Semiconductor device and method of manufacture

ABSTRACT

A semiconductor device has a conductive via laterally separated from the semiconductor, an encapsulant between the semiconductor device and the conductive via, and a mark. The mark is formed from characters that are either cross-free characters or else have a overlap count of less than two. In another embodiment the mark is formed using a wobble scan methodology. By forming marks as described, defects from the marking process may be reduced or eliminated.

PRIORITY CLAIM AND CROSS-REFERENCE

This application is a continuation of U.S. patent application Ser. No.17/079,704, entitled, “Semiconductor Device and Method of Manufacture,”filed on Oct. 26, 2020, which is a continuation of U.S. patentapplication Ser. No. 16/518,568, entitled, “Semiconductor Device andMethod of Manufacture,” filed on Jul. 22, 2019, now U.S. Pat. No.10,818,607 issued on Oct. 27, 2020, which is a continuation of U.S.patent application Ser. No. 15/670,187, entitled, “Semiconductor Deviceand Method of Manufacture,” filed on Aug. 7, 2017, now U.S. Pat. No.10,361,161, issued on Jul. 23, 2019, which is a continuation of U.S.patent application Ser. No. 14/857,939, entitled, “Semiconductor Deviceand Method of Manufacture,” filed on Sep. 18, 2015, now U.S. Pat. No.9,728,508, issued on Aug. 8, 2017, which applications are herebyincorporated herein by reference.

BACKGROUND

The semiconductor industry has experienced rapid growth due tocontinuous improvements in the integration density of a variety ofelectronic components (e.g., transistors, diodes, resistors, capacitors,etc.). For the most part, this improvement in integration density hascome from repeated reductions in minimum feature size (e.g., shrinkingthe semiconductor process node towards the sub-20 nm node), which allowsmore components to be integrated into a given area. As the demand forminiaturization, higher speed and greater bandwidth, as well as lowerpower consumption and latency has grown recently, there has grown a needfor smaller and more creative packaging techniques of semiconductordies.

As semiconductor technologies further advance, stacked and bondedsemiconductor devices have emerged as an effective alternative tofurther reduce the physical size of a semiconductor device. In a stackedsemiconductor device, active circuits such as logic, memory, processorcircuits and the like are fabricated at least partially on separatesubstrates and then physically and electrically bonded together in orderto form a functional device. Such bonding processes utilizesophisticated techniques, and improvements are desired.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 illustrates a formation of through vias in accordance with someembodiments.

FIG. 2 illustrates a first semiconductor device in accordance with someembodiments.

FIG. 3 illustrates a placement of the first semiconductor device and asecond semiconductor device in accordance with some embodiments.

FIG. 4 illustrates a placement of an encapsulant in accordance with someembodiments.

FIG. 5 illustrates a formation of a redistribution layer in accordancewith some embodiments.

FIG. 6 illustrates a removal of a carrier wafer in accordance with someembodiments.

FIG. 7 illustrates a formation of openings in accordance with someembodiments.

FIGS. 8A-8B illustrates a marking process in accordance with someembodiments.

FIGS. 9A-9B illustrate an alphanumeric character formed using themarking process in accordance with some embodiments.

FIG. 10 illustrates a set of alphanumeric characters in accordance withsome embodiments.

FIG. 11 illustrates a reduced cross marking process in accordance withsome embodiments.

FIG. 12 illustrates placing the mark over the encapsulant in accordancewith some embodiments.

FIG. 13 illustrates a wobble scan in accordance with some embodiments.

FIG. 14 illustrates a specific example of a marking formed using thewobble scan in accordance with some embodiments.

FIG. 15 illustrates a package on package in accordance with someembodiments.

FIG. 16 illustrates a singulation of the package on package structure inaccordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the invention. Specificexamples of components and arrangements are described below to simplifythe present disclosure. These are, of course, merely examples and arenot intended to be limiting. For example, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed between the first and second features, such thatthe first and second features may not be in direct contact. In addition,the present disclosure may repeat reference numerals and/or letters inthe various examples. This repetition is for the purpose of simplicityand clarity and does not in itself dictate a relationship between thevarious embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

With reference now to FIG. 1 , there is shown a first carrier substrate101 with an adhesive layer 103, a polymer layer 105, and a first seedlayer 107 over the first carrier substrate 101. The first carriersubstrate 101 comprises, for example, silicon based materials, such asglass or silicon oxide, or other materials, such as aluminum oxide,combinations of any of these materials, or the like. The first carriersubstrate 101 is planar in order to accommodate an attachment ofsemiconductor devices such as a first semiconductor device 201 and asecond semiconductor device 301 (not illustrated in FIG. 1 butillustrated and discussed below with respect to FIGS. 2-3 ).

The adhesive layer 103 is placed on the first carrier substrate 101 inorder to assist in the adherence of overlying structures (e.g., thepolymer layer 105). In an embodiment the adhesive layer 103 may comprisean ultra-violet glue, which loses its adhesive properties when exposedto ultra-violet light. However, other types of adhesives, such aspressure sensitive adhesives, radiation curable adhesives, epoxies,combinations of these, or the like, may also be used. The adhesive layer103 may be placed onto the first carrier substrate 101 in a semi-liquidor gel form, which is readily deformable under pressure.

The polymer layer 105 is placed over the adhesive layer 103 and isutilized in order to provide protection to, e.g., the firstsemiconductor device 201 and the second semiconductor device 301 oncethe first semiconductor device 201 and the second semiconductor device301 have been attached. In an embodiment the polymer layer 105 may bepolybenzoxazole (PBO), although any suitable material, such aspolyimide, a polyimide derivative, a Solder Resistance (SR), anAjinomoto build-up film (ABF), or the like may alternatively beutilized. The polymer layer 105 may be placed using, e.g., aspin-coating process to a first thickness Ti of between about 0.5 μm andabout 10 μm, such as about 5 μm, although any suitable method andthickness may alternatively be used.

The first seed layer 107 is formed over the polymer layer 105. In anembodiment the first seed layer 107 is a thin layer of a conductivematerial that aids in the formation of a thicker layer during subsequentprocessing steps. The first seed layer 107 may comprise a layer oftitanium followed by a layer of copper, although any other suitablematerial or combination of materials, such as a single layer of copper,may also be used. The first seed layer 107 may be created usingprocesses such as sputtering, evaporation, or PECVD processes, dependingupon the desired materials.

FIG. 1 also illustrates a placement and patterning of a photoresist 109over the first seed layer 107. In an embodiment the photoresist 109 maybe placed on the first seed layer 107 using, e.g., a spin coatingtechnique to a height of between about 50 μm and about 250 μm. Once inplace, the photoresist 109 may then be patterned by exposing thephotoresist 109 to a patterned energy source (e.g., a patterned lightsource) so as to induce a chemical reaction, thereby inducing a physicalchange in those portions of the photoresist 109 exposed to the patternedlight source. A developer is then applied to the exposed photoresist 109to take advantage of the physical changes and selectively remove eitherthe exposed portion of the photoresist 109 or the unexposed portion ofthe photoresist 109, depending upon the desired pattern.

In an embodiment the pattern formed into the photoresist 109 is apattern for vias 111. The vias 111 are formed in such a placement as tobe located on different sides of subsequently attached devices such asthe first semiconductor device 201 and the second semiconductor device301. However, any suitable arrangement for the pattern of vias 111, suchas by being located such that the first semiconductor device 201 and thesecond semiconductor device are placed on opposing sides of the vias111, may alternatively be utilized.

In an embodiment the vias 111 are formed within the photoresist 109. Inan embodiment the vias 111 comprise one or more conductive materials,such as copper, tungsten, other conductive metals, or the like, and maybe formed, for example, by electroplating, electroless plating, or thelike. In an embodiment, an electroplating process is used wherein thefirst seed layer 107 and the photoresist 109 are submerged or immersedin an electroplating solution. The first seed layer 107 surface iselectrically connected to the negative side of an external DC powersupply such that the first seed layer 107 functions as the cathode inthe electroplating process. A solid conductive anode, such as a copperanode, is also immersed in the solution and is attached to the positiveside of the power supply. The atoms from the anode are dissolved intothe solution, from which the cathode, e.g., the first seed layer 107,acquires the dissolved atoms, thereby plating the exposed conductiveareas of the first seed layer 107 within the opening of the photoresist109.

Once the vias 111 have been formed using the photoresist 109 and thefirst seed layer 107, the photoresist 109 may be removed using asuitable removal process (not illustrated in FIG. 1 but seen in FIG. 3below). In an embodiment, a plasma ashing process may be used to removethe photoresist 109, whereby the temperature of the photoresist 109 maybe increased until the photoresist 109 experiences a thermaldecomposition and may be removed. However, any other suitable process,such as a wet strip, may alternatively be utilized. The removal of thephotoresist 109 may expose the underlying portions of the first seedlayer 107.

Once exposed a removal of the exposed portions of the first seed layer107 may be performed (not illustrated in FIG. 1 but seen in FIG. 3below). In an embodiment the exposed portions of the first seed layer107 (e.g., those portions that are not covered by the vias 111) may beremoved by, for example, a wet or dry etching process. For example, in adry etching process reactants may be directed towards the first seedlayer 107 using the vias 111 as masks. In another embodiment, etchantsmay be sprayed or otherwise put into contact with the first seed layer107 in order to remove the exposed portions of the first seed layer 107.After the exposed portion of the first seed layer 107 has been etchedaway, a portion of the polymer layer 105 is exposed between the vias111.

FIG. 2 illustrates a first semiconductor device 201 that will beattached to the polymer layer 105 within the vias 111 (not illustratedin FIG. 2 but illustrated and described below with respect to FIG. 3 ).In an embodiment the first semiconductor device 201 comprises a firstsubstrate 203, first active devices (not individually illustrated),first metallization layers 205, first contact pads 207, a firstpassivation layer 211, and first external connectors 209. The firstsubstrate 203 may comprise bulk silicon, doped or undoped, or an activelayer of a silicon-on-insulator (SOI) substrate. Generally, an SOIsubstrate comprises a layer of a semiconductor material such as silicon,germanium, silicon germanium, SOI, silicon germanium on insulator(SGOI), or combinations thereof. Other substrates that may be usedinclude multi-layered substrates, gradient substrates, or hybridorientation substrates.

The first active devices comprise a wide variety of active devices andpassive devices such as capacitors, resistors, inductors and the likethat may be used to generate the desired structural and functionalrequirements of the design for the first semiconductor device 201. Thefirst active devices may be formed using any suitable methods eitherwithin or else on the first substrate 203.

The first metallization layers 205 are formed over the first substrate203 and the first active devices and are designed to connect the variousactive devices to form functional circuitry. In an embodiment the firstmetallization layers 205 are formed of alternating layers of dielectricand conductive material and may be formed through any suitable process(such as deposition, damascene, dual damascene, etc.). In an embodimentthere may be four layers of metallization separated from the firstsubstrate 203 by at least one interlayer dielectric layer (ILD), but theprecise number of first metallization layers 205 is dependent upon thedesign of the first semiconductor device 201.

The first contact pads 207 may be formed over and in electrical contactwith the first metallization layers 205. The first contact pads 207 maycomprise aluminum, but other materials, such as copper, mayalternatively be used. The first contact pads 207 may be formed using adeposition process, such as sputtering, to form a layer of material (notshown) and portions of the layer of material may then be removed througha suitable process (such as photolithographic masking and etching) toform the first contact pads 207. However, any other suitable process maybe utilized to form the first contact pads 207.

The first passivation layer 211 may be formed on the first substrate 203over the first metallization layers 205 and the first contact pads 207.The first passivation layer 211 may be made of one or more suitabledielectric materials such as silicon oxide, silicon nitride, low-kdielectrics such as carbon doped oxides, extremely low-k dielectricssuch as porous carbon doped silicon dioxide, combinations of these, orthe like. The first passivation layer 211 may be formed through aprocess such as chemical vapor deposition (CVD), although any suitableprocess may be utilized.

The first external connectors 209 may be formed to provide conductiveregions for contact between the first contact pads 207 and, e.g., aredistribution layer 501 (not illustrated in FIG. 2 but illustrated anddescribed below with respect to FIG. 5 ). In an embodiment the firstexternal connectors 209 may be conductive pillars and may be formed byinitially forming a photoresist (not shown) over the first passivationlayer 211 to a thickness between about 5 μm to about 20 μm. Thephotoresist may be patterned to expose portions of the first passivationlayers 211 through which the conductive pillars will extend. Oncepatterned, the photoresist may then be used as a mask to remove thedesired portions of the first passivation layer 211, thereby exposingthose portions of the underlying first contact pads 207 to which thefirst external connectors 209 will make contact.

The first external connectors 209 may be formed within the openings ofboth the first passivation layer 211 and the photoresist. The firstexternal connectors 209 may be formed from a conductive material such ascopper, although other conductive materials such as nickel, gold, ormetal alloy, combinations of these, or the like may also be used.Additionally, the first external connectors 209 may be formed using aprocess such as electroplating, by which an electric current is runthrough the conductive portions of the first contact pads 207 to whichthe first external connectors 209 are desired to be formed, and thefirst contact pads 207 are immersed in a solution. The solution and theelectric current deposit, e.g., copper, within the openings in order tofill and/or overfill the openings of the photoresist and the firstpassivation layer 211, thereby forming the first external connectors209. Excess conductive material and photoresist outside of the openingsof the first passivation layer 211 may then be removed using, forexample, an ashing process, a chemical mechanical polish (CMP) process,combinations of these, or the like.

However, as one of ordinary skill in the art will recognize, the abovedescribed process to form the first external connectors 209 is merelyone such description, and is not meant to limit the embodiments to thisexact process. Rather, the described process is intended to be merelyillustrative, as any suitable process for forming the first externalconnectors 209 may alternatively be utilized. All suitable processes arefully intended to be included within the scope of the presentembodiments.

A die attach film (DAF) 217 may be placed on an opposite side of thefirst substrate 203 in order to assist in the attachment of the firstsemiconductor device 201 to the polymer layer 105. In an embodiment thedie attach film 217 is an epoxy resin, a phenol resin, acrylic rubber,silica filler, or a combination thereof, and is applied using alamination technique. However, any other suitable alternative materialand method of formation may alternatively be utilized.

FIG. 3 illustrates a placement of the first semiconductor device 201onto the polymer layer 105 along with a placement of the secondsemiconductor device 301. In an embodiment the second semiconductordevice 301 may comprise a second substrate 303, second active devices(not individually illustrated), second metallization layers 305, secondcontact pads 307, a second passivation layer 311, and second externalconnectors 309. In an embodiment the second substrate 303, the secondactive devices, the second metallization layers 305, the second contactpads 307, the second passivation layer 311, and the second externalconnectors 309 may be similar to the first substrate 203, the firstactive devices, the first metallization layers 205, the first contactpads 207, the first passivation layer 211, and the first externalconnectors 209, although they may also be different.

In an embodiment the first semiconductor device 201 and the secondsemiconductor device 301 may be placed onto the polymer layer 105 using,e.g., a pick and place process. However, any other method of placing thefirst semiconductor device 201 and the second semiconductor device 301may also be utilized.

FIG. 4 illustrates an encapsulation of the vias 111, the firstsemiconductor device 201 and the second semiconductor device 301. Theencapsulation may be performed in a molding device (not individuallyillustrated in FIG. 4 ), which may comprise a top molding portion and abottom molding portion separable from the top molding portion. When thetop molding portion is lowered to be adjacent to the bottom moldingportion, a molding cavity may be formed for the first carrier substrate101, the vias 111, the first semiconductor device 201, and the secondsemiconductor device 301.

During the encapsulation process the top molding portion may be placedadjacent to the bottom molding portion, thereby enclosing the firstcarrier substrate 101, the vias 111, the first semiconductor device 201,and the second semiconductor device 301 within the molding cavity. Onceenclosed, the top molding portion and the bottom molding portion mayform an airtight seal in order to control the influx and outflux ofgasses from the molding cavity. Once sealed, an encapsulant 401 may beplaced within the molding cavity. The encapsulant 401 may be a moldingcompound resin such as polyimide, PPS, PEEK, PES, a heat resistantcrystal resin, combinations of these, or the like. The encapsulant 401may be placed within the molding cavity prior to the alignment of thetop molding portion and the bottom molding portion, or else may beinjected into the molding cavity through an injection port.

Once the encapsulant 401 has been placed into the molding cavity suchthat the encapsulant 401 encapsulates the first carrier substrate 101,the vias 111, the first semiconductor device 201, and the secondsemiconductor device 301, the encapsulant 401 may be cured in order toharden the encapsulant 401 for optimum protection. While the exactcuring process is dependent at least in part on the particular materialchosen for the encapsulant 401, in an embodiment in which moldingcompound is chosen as the encapsulant 401, the curing could occurthrough a process such as heating the encapsulant 401 to between about100° C. and about 130° C. for about 60 sec to about 3000 sec.Additionally, initiators and/or catalysts may be included within theencapsulant 401 to better control the curing process.

However, as one having ordinary skill in the art will recognize, thecuring process described above is merely an exemplary process and is notmeant to limit the current embodiments. Other curing processes, such asirradiation or even allowing the encapsulant 401 to harden at ambienttemperature, may alternatively be used. Any suitable curing process maybe used, and all such processes are fully intended to be included withinthe scope of the embodiments discussed herein.

FIG. 4 also illustrates a thinning of the encapsulant 401 in order toexpose the vias 111, the first semiconductor device 201, and the secondsemiconductor device 301 for further processing. The thinning may beperformed, e.g., using a mechanical grinding or chemical mechanicalpolishing (CMP) process whereby chemical etchants and abrasives areutilized to react and grind away the encapsulant 401, the firstsemiconductor device 201 and the second semiconductor device 301 untilthe vias 111, the first external connectors 209 (on the firstsemiconductor device 201), and the second external connectors 309 (onthe second semiconductor device 301) have been exposed. As such, thefirst semiconductor device 201, the second semiconductor device 301, andthe vias 111 may have a planar surface that is also planar with theencapsulant 401.

By thinning the encapsulant 401 such that the vias 111, the firstsemiconductor device 201, and the second semiconductor device 301 areexposed, there is a first region 403 of encapsulant 401 that is locatedbetween the vias 111 and the first semiconductor device 201. In anembodiment the first region 403 of the encapsulant 401 may have a firstwidth W₁ of between about 150 μm and about 1600 μm, such as about 850μm. However, any suitable dimensions may be utilized.

However, while the CMP process described above is presented as oneillustrative embodiment, it is not intended to be limiting to theembodiments. Any other suitable removal process may alternatively beused to thin the encapsulant 401, the first semiconductor device 201,and the second semiconductor device 301 and expose the vias 111. Forexample, a series of chemical etches may be utilized. This process andany other suitable process may alternatively be utilized to thin theencapsulant 401, the first semiconductor device 201, and the secondsemiconductor device 301, and all such processes are fully intended tobe included within the scope of the embodiments.

Optionally, if desired the vias 111 may be recessed within theencapsulant 401. In an embodiment the recessing may be performed usingan etching process such as a wet or dry etching process that selectivelyremoves the exposed surface of the vias 111 without substantiallyremoving the surrounding encapsulant 401 so that the vias 111 arerecessed. In an embodiment the recessing may be performed so that thevias 111 are recessed between about 0.05 μm and about 2 μm, such asabout 0.1 μm.

FIG. 5 illustrates a formation of a redistribution layer (RDL) 501 inorder to interconnect the first semiconductor device 201, the secondsemiconductor device 301, the vias 111 and the third external connectors505. By using the RDL 501 to interconnect the first semiconductor device201 and the second semiconductor device 301, the first semiconductordevice 201 and the second semiconductor device 301 may have a pin countof greater than 1000.

In an embodiment the RDL 501 may be formed by initially forming a secondseed layer (not shown) of a titanium copper alloy through a suitableformation process such as CVD or sputtering. A photoresist (also notshown) may then be formed to cover the second seed layer, and thephotoresist may then be patterned to expose those portions of the secondseed layer that are located where the RDL 501 is desired to be located.

Once the photoresist has been formed and patterned, a conductivematerial, such as copper, may be formed on the second seed layer througha deposition process such as plating. However, while the material andmethods discussed are suitable to form the conductive material, thesematerials are merely exemplary. Any other suitable materials, such asAlCu or Au, and any other suitable processes of formation, such as CVDor PVD, may alternatively be used to form the RDL 501.

Once the conductive material has been formed, the photoresist may beremoved through a suitable removal process such as ashing. Additionally,after the removal of the photoresist, those portions of the second seedlayer that were covered by the photoresist may be removed through, forexample, a suitable etch process using the conductive material as amask.

FIG. 5 also illustrates a formation of a third passivation layer 503over the RDL 501 in order to provide protection and isolation for theRDL 501 and the other underlying structures. In an embodiment the thirdpassivation layer 503 may be polybenzoxazole (PBO), although anysuitable material, such as polyimide or a polyimide derivative, mayalternatively be utilized. The third passivation layer 503 may be placedusing, e.g., a spin-coating process, although any suitable method mayalternatively be used.

In an embodiment the thickness of the structure from the thirdpassivation layer 503 to the polymer layer 105 may be less than or equalto about 200 μm. By making this thickness as small as possible, theoverall structure may be utilized in various small size applications,such as cell phones and the like, while still maintaining the desiredfunctionality. However, as one of ordinary skill in the art willrecognize, the precise thickness of the structure may be dependent atleast in part upon the overall design for the unit and, as such, anysuitable thickness may alternatively be utilized.

Additionally, while only a single RDL 501 is illustrated in FIG. 5 ,this is intended for clarity and is not intended to limit theembodiments. Rather, any suitable number of conductive and passivationlayers, such as three RDL 501 layers, may be formed by repeating theabove described process to form the RDL 501. Any suitable number oflayers may be utilized.

FIG. 5 further illustrates a formation of the third external connectors505 to make electrical contact with the RDL 501. In an embodiment afterthe third passivation layer 503 has been formed, an opening may be madethrough the third passivation layer 503 by removing portions of thethird passivation layer 503 to expose at least a portion of theunderlying RDL 501. The opening allows for contact between the RDL 501and the third external connectors 505. The opening may be formed using asuitable photolithographic mask and etching process, although anysuitable process to expose portions of the RDL 501 may be used.

In an embodiment the third external connectors 505 may be placed on theRDL 501 through the third passivation layer 503 and may be a ball gridarray (BGA) which comprises a eutectic material such as solder, althoughany suitable materials may alternatively be used. Optionally, anunderbump metallization (not separately illustrated) may be utilizedbetween the third external connectors 505 and the RDL 501. In anembodiment in which the third external connectors 505 are solder balls,the third external connectors 505 may be formed using a ball dropmethod, such as a direct ball drop process. Alternatively, the solderballs may be formed by initially forming a layer of tin through anysuitable method such as evaporation, electroplating, printing, soldertransfer, and then performing a reflow in order to shape the materialinto the desired bump shape. Once the third external connectors 505 havebeen formed, a test may be performed to ensure that the structure issuitable for further processing.

FIG. 6 illustrates a debonding of the first carrier substrate 101 fromthe first semiconductor device 201 and the second semiconductor device301. In an embodiment the third external connectors 505 and, hence, thestructure including the first semiconductor device 201 and the secondsemiconductor device 301, may be attached to a ring structure 601. Thering structure 601 may be a metal ring intended to provide support andstability for the structure during and after the debonding process. Inan embodiment the third external connectors 505, the first semiconductordevice 201, and the second semiconductor device 301 are attached to thering structure using, e.g., a ultraviolet tape 603, although any othersuitable adhesive or attachment may alternatively be used.

Once the third external connectors 505 and, hence, the structureincluding the first semiconductor device 201 and the secondsemiconductor device 301 are attached to the ring structure 601, thefirst carrier substrate 101 may be debonded from the structure includingthe first semiconductor device 201 and the second semiconductor device301 using, e.g., a thermal process to alter the adhesive properties ofthe adhesive layer 103. In a particular embodiment an energy source suchas an ultraviolet (UV) laser, a carbon dioxide (CO₂) laser, or aninfrared (IR) laser, is utilized to irradiate and heat the adhesivelayer 103 until the adhesive layer 103 loses at least some of itsadhesive properties. Once performed, the first carrier substrate 101 andthe adhesive layer 103 may be physically separated and removed from thestructure comprising the third external connectors 505, the firstsemiconductor device 201, and the second semiconductor device 301.

FIG. 7 illustrates a patterning of the polymer layer 105 in order toexpose the vias 111 (along with the associated first seed layer 107). Inan embodiment the polymer layer 105 may be patterned using, e.g., alaser drilling method. In such a method a protective layer, such as alight-to-heat conversion (LTHC) layer or a hogomax layer (not separatelyillustrated in FIG. 7 ) is first deposited over the polymer layer 105.Once protected, a laser is directed towards those portions of thepolymer layer 105 which are desired to be removed in order to expose theunderlying vias 111. During the laser drilling process the drill energymay be in a range from 0.1 mJ to about 30 mJ, and a drill angle of about0 degree (perpendicular to the polymer layer 105) to about 85 degrees tonormal of the polymer layer 105. In an embodiment the patterning may beformed to form first openings 703 over the vias 111 to have a width ofbetween about 100 μm and about 300 μm, such as about 200 μm. Once thefirst openings 703 have been formed with the laser drilling method, thefirst openings 703 may be cleaned to remove any laser drill residue.

In another embodiment, the polymer layer 105 may be patterned byinitially applying a photoresist (not individually illustrated in FIG. 7) to the polymer layer 105 and then exposing the photoresist to apatterned energy source (e.g., a patterned light source) so as to inducea chemical reaction, thereby inducing a physical change in thoseportions of the photoresist exposed to the patterned light source. Adeveloper is then applied to the exposed photoresist to take advantageof the physical changes and selectively remove either the exposedportion of the photoresist or the unexposed portion of the photoresist,depending upon the desired pattern, and the underlying exposed portionof the polymer layer 105 are removed with, e.g., a dry etch process.However, any other suitable method for patterning the polymer layer 105may be utilized.

FIG. 8A illustrates a cross-sectional view of a marking process(represented in FIG. 8A by the dashed cylinder labeled 801) that isutilized to mark the polymer layer 105 with a desired identifying mark805 (which mark 805 merely appears as second openings 802 in thiscross-sectional view of FIG. 8A). In an embodiment the marking processmay be, for example, a laser marking process which is used to mark thepolymer layer 105 with, e.g., a run number, a manufacturer identifier, adate of manufacture, combinations of these, or the like, with one ormore alphanumeric characters as the mark 805. However, any othersuitable desired identifying or information mark 805 may be used.

In an embodiment the marking process 801 is utilized to form secondopenings 802 (also known as kerfs) within the polymer layer 105, whereinwhen each one of the second openings 802 is taken in combination withone or more of the other second openings 802, the combination of secondopenings 802 collectively form the desired mark 805 in, e.g., a top downview. However, if the second openings 802 extend too far into thepolymer layer 105 or even through the polymer layer 105, there is apossibility that defects may occur from exposure of the underlying firstsemiconductor device 201 and the second semiconductor device 301, orthat, even if the second openings 802 do not extend all of the waythrough the polymer layer 105, damage may occur due to induced heat spoteffects, which could further damage the RDL 501 or the overall functionsof the first semiconductor device 201 and the second semiconductordevice 301.

FIG. 8B illustrates a top-down view of one embodiment of the markingprocess 801 which may be used to mitigate or eliminate these issuesduring the marking process 801. For clarity, FIG. 8B illustrates aformation of a single first line 807 in an embodiment in which themarking process 801 is a laser marking process, although the first line807 may be utilized along with other lines (such as a second line 901and a third line 903, not illustrated in FIG. 8B but illustrated anddescribed further below with respect to FIG. 9A) in order to form anydesired shape for the mark 805. In an embodiment the laser markingprocess may be performed by irradiating the polymer layer 105 with aseries of laser pulses (two of which are represented in FIG. 8B by thedashed cylinders labeled 804 ₁ and 804 ₂ and the rest of which have beenremoved for clarity) to form the second openings (see FIG. 8A), whereineach one of the series of laser beam pulses 804 forms a laser beam pulseexposure (each of which is represented in FIG. 8B by the dashed circleslabeled 809 ₁, 809 ₂, 809 _(n-1), 809 _(n), etc.).

For example, to begin the laser marking process, a portion of thepolymer layer 105 that is desired to be marked may be irradiated with afirst one of the laser beam pulses 804 ₁ that has a first diameter D₁ ofbetween about 20 μm and about 120 μm, such as about 50 μm, that is equalto the desired dot width W_(d) of the first line 807. Additionally, thefirst one of the laser beam pulses 804 ₁ may have an energy density ofbetween about 1.0×10⁻³ J/mm² and about 5.0×10⁻² J/mm², such as about1.5×10⁻² J/mm². Once the polymer layer 105 has been irradiated, thefirst one of the laser beam pulses 804 ₁ may be maintained for a time ofbetween about 1.0×10⁻⁵ sec and about 8.0×10⁻⁵ sec, such as about2.8×10⁻⁵ sec, in order to pulse the laser beam and form the first laserbeam pulse exposure 809 ₁ on the polymer layer 105. During this firstone of the laser beam pulses 804 ₁, a portion of the polymer layer 105is removed to form a first one of the first laser beam pulse exposures809 ₁.

Once the first one of the first laser pulse exposures 809 ₁ has beenformed, the first one of the laser beam pulses 804 ₁ is halted. At thattime, the laser beam may be moved into position to irradiate the polymerlayer 105 with a second one of the laser beam pulses 804 ₂ in order toform a second laser beam pulse exposure 809 ₂ which overlaps the firstlaser beam pulse exposure 809 ₁. In an embodiment the second laser beampulse exposure 809 ₂ is offset from the first laser beam pulse exposure809 ₁ by a first pitch Pi of between about 2 μm and about 70 μm, such asabout 5.7 μm. The second one of the laser beam pulses 804 ₂ may besimilar to the first one of the laser beam pulses 804 ₁, such as byhaving the first diameter D₁, although any other suitable parameters forthe second one of the laser beam pulses 804 ₂ may be utilized.

After forming the second laser beam pulse exposure 809 ₂ overlapping thefirst laser beam pulse exposure 809 ₁, the second one of the laser beampulses 804 ₂ is halted. At that time, the laser beam may be moved intoposition to irradiate another portion of the polymer layer 105 in orderto form a third laser beam pulse exposure 809 ₃, which overlaps both thefirst laser beam pulse exposure 809 ₁ and the second laser beam pulseexposure 809 ₂. This process of using offset laser beam pulses 804 toform overlapping but offset laser beam pulse exposures 809 within thepolymer layer 105 may be continued to form the first line 807, whereinthe desired length of the first line 807 is determined by the number oflaser beam pulses 804 used to form a desired number of laser beam pulseexposures 809.

However, by overlapping the laser beam pulse exposures 809 (e.g., thefirst laser beam pulse exposure 809 ₁ is overlapped by at least thesecond laser beam pulse exposure 809 ₂ and the third laser beam pulseexposure 809 ₃), there will be portions of the laser beam pulseexposures 809 that have been irradiated by multiple ones of the laserbeam pulses 804, with each exposure removing additional material fromthe polymer layer 105 and causing different kerf depths even within thesame laser beam pulse exposure 809 (e.g., the first laser beam pulseexposure 809 ₁). For example, looking at a fully exposed laser beampulse exposure 811 (one which is located within an interior of the firstline 807 and not at a terminating end of the first line 807 such thatthere is a maximum overlap amount), there may be a total accumulatedoverlap within the fully exposed laser beam pulse exposure 811 ofbetween about 100% and about 400%, such as about 376%.

However, when each one of the laser beam pulse exposures 809 isoverlapped by a neighboring laser beam pulse exposure 809, each one ofthe laser beam pulses 804 will remove additional material from thepolymer layer 105. For example, in making the first line 807 with afirst pass of the laser beam pulses 804, while the individual laser beampulse exposure 809 may have different depths within the individual laserbeam pulse exposures 809, the laser beam pulse exposures 809 may begenerally formed to have a deepest first depth D₁ that is less than thefirst thickness Ti (see FIG. 1 ) of the polymer layer 105, such as bybeing between about 2 μm and about 10 μm, such as less than about 7.52μm.

Additionally, in order to help with the overlapping between theindividual ones of the laser beam pulse exposures 809, in an embodimenta path angle should be maintained low so that additional overlappingdoes not occur between a first portion of the first line 807 and asecond portion of the first line 807 that is at an angle to the firstportion of the first line 807. For example, in an embodiment the markingpath may be maintained to have a first angle α₁ of between about 20° andabout 90°, such as less than about 30°. However, any suitable firstangle α₁ may be used.

FIG. 9A illustrates one embodiment that may be used to reduce oreliminate the defects caused by the marking process 801. In thisembodiment, the first line 807 (illustrated with a curved portion) isutilized along with a second line 901 and a third line 903 tocollectively form a letter “Q” within the polymer layer 105. In anembodiment the second line 901 and the third line 903 may be formedusing a similar process as the first line 807. For example, a series oflaser beam pulses 804 may be used to form overlapping laser beam pulseexposures 809 within the polymer layer 105, wherein the combination oflaser beam pulse exposures 809 collectively form the second line 901and, separately, form the third line 903.

However, in order to prevent any additional removal of the material ofthe polymer layer 105 beyond the material already removed during theformation of the individual lines (discussed above with respect to FIG.8B), the mark 805 (e.g., the character “Q”) is formed such that there isan overlap count (or a number of passes over a spot) less than one suchthat the mark 805 is formed to be cross free. For example, the firstline 807 may be formed such that the first line 807 does not intersector overlap either the second line 901 or the third line 903. Similarly,the second line 901 is formed such that the second line 901 does notintersect or overlap either the first line 807 or the third line 903.

Such a prevention creates regions of separation 902 (wherein alongitudinal axis of a first line intersects a longitudinal axis of asecond line) wherein the lines that are used to form the desiredcharacter (e.g., the first line 807, the second line 901, and the thirdline 903 to form the letter “Q”) collectively form a discontinuousshape. By forming such a discontinuous shape, sections where the lineswould have previously intersected and caused undesired anduncontrollable kerf depths may be prevented, and the first depth D₁within the region of separation 902 is the same as the first depth D₁outside of the region of separation 902 (whereas previously the depthshave been different when there are multiple passes of the laser beams).As such, fewer defects may arise during the formation of the mark 805.In an embodiment the separation between lines (e.g., between the secondline 901 and the third line 903) may be a first distance D₁ of betweenabout 10 μm and about 50 μm, such as about 25 μm.

FIG. 9B illustrates additional embodiments of other alphanumericcharacters that may be used to form the mark 805 similar to the “Q”illustrated above with respect to FIG. 9A. In particular, FIG. 9Billustrates the lower case letters “r” 905, “a” 907, and “g” 909 thatare formed with the cross-free methodology and design. As can be seen,each of these letters is designed and formed with regions of separation902 in those areas where lines would otherwise intersect.

FIG. 10 illustrates additional embodiments of alphanumeric charactersthat may be utilized with the cross-free marking process 801. In thiscollection of alphanumerical upper case and lower case characters, therecan be seen regions of separation 902 within some of the individualletters (e.g., the letter “T”), although not every letter has a regionof separation 902 (e.g., the letter “L”). In each of these regions ofseparation 902, the laser marking process forms a separation betweenlines so as to prevent or mitigate the additional removal of additionalmaterial from the polymer layer 105 during the formation of intersectinglines.

By eliminating the overlap between lines, a more controllable kerf depthmay be obtained, and package die damage from heat spot effects that canoccur and damage the RDL 501, the first semiconductor device 201, andthe second semiconductor device 301 when the polymer layer 105 becomesthinner during an uncontrolled marking processes may be reduced oreliminated. As such, a thinner polymer layer 105 may be used whilemaintaining an effective thermal control and an overall form factorreduction may be achieved while also improving the overall yield ofmanufactured devices.

For example, in a particular embodiment the first depth D₁ within anindividual one of the laser beam pulse exposures 809 (see FIG. 8B) mayvary between 6.87 μm to 8.03 μm, with an average of about 7.455 μm and avariation of about 1.16 μm. This is lower than in a multiple pass,non-cross-free method, in which the depth may vary from 13.25 μm and15.92 μm, with an average of 14.757 μm and a variation of 2.67 μm. Inanother description, by using a cross-free method, the first depth D₁ isthe depth of a single pass of the laser beam, such as about 7.52 μm,while multiple passes of the laser beam, such as two-passes of the laserbeam with an overlap count of 2, may have a depth of 15.8 μm. Byreducing the marking depth, the defects that may occur because of theundesired removal of additional material from the polymer layer 105 maybe reduced or eliminated.

FIG. 11 illustrates another embodiment in which the lines within adesired identifying mark 805 may have a reduced overlap count (e.g., anoverlap count of less than two) but in which the lines may still have anoverlap count greater than one. In this embodiment, rather than having across-free character where the individual lines do not intersect, theindividual lines within a character may have an overlap count of lessthan about 2 in an area of intersection between, e.g., the first line807 with a fourth line 1101. In an embodiment the fourth line 1101 maybe formed using a similar process as the one described above withrespect to FIG. 8B. For example, a series of laser beam pulses 804 (notseparately illustrated in FIG. 11 ) are used to form laser beam pulseexposures 809 that overlap with each other within the fourth line 1101to remove material from the polymer layer 105 and form the fourth line1101, although any suitable method may be utilized.

In this embodiment, however, instead of keeping the first line 807 andthe fourth line 1101 from intersecting with each other (and having anoverlap count less than one), a partial intersection between the firstline 807 and the fourth line 1101 may be made, wherein the laser beampulse exposures 809 may extend partially into the fourth line 1101.However, instead of the first line 807 extending all of the way into thefourth line 1101 (wherein one of the laser beam pulse exposures 809 fromthe first line 807 is fully overlapped by the fourth line 1101, therebyhaving an overlap count of 2), the first line 807 may partially extendinto the fourth line 1101 so that the first line 807 has an overlapcount of less than about 2.

In this embodiment, an intersecting laser beam pulse exposure 809 ₄(highlighted in FIG. 11 by the shaded region) is part of the first line807, but also extends at least partially into the fourth line 1101.However, by limiting the intersection of the first line 807 and thefourth line 1101, the amount of overlap may be kept small and defectsmay be minimized. In an embodiment the overlap count for theintersecting laser beam pulse exposure 809 ₄ is less than two and has anaccumulated overlap percentage (between overlapping laser beam pulseexposures 809 from both the first line 807 and the fourth line 1101)greater than about 376% and less than 752%, such as about 564%.

Such a prevention also forms the first depth D₁ (see FIG. 8A) within thepolymer layer 105 to have a different depth within the region ofintersection than outside of the region of intersection (as there havebeen additional exposures of the material of the polymer layer 105 tothe laser beams). As such, in an embodiment, the first depth D₁ withinthe intersecting laser beam pulse exposure 809 ₄ may be between about 5μm and about 18 μm, such as about 14 μm. However, any suitable depth maybe used.

Additionally in the embodiment illustrated in FIG. 11 , in order to helpwith the overlapping between the individual ones of the laser beam pulseexposures 809, in an embodiment the path angle should be maintained lowso that additional overlapping does not occur between a first portion ofthe first line 807 and a second portion of the first line 807. Forexample, in an embodiment the marking path may be maintained to have asecond angle α₂ of between about 20° and about 90°, such as less thanabout 88°. However, any suitable second angle α₂ may be used.

By limiting the amount of overlap between intersecting lines (e.g., thefirst line 807 and the fourth line 1101), defects that may occur due tothe marking process 801 may be reduced without completely separating theintersecting lines. As such, defects may be reduced or mitigated whilestill forming an intersection between the lines used to form the mark805.

FIG. 12 illustrates yet another embodiment in which one or more of themarks 805 (formed using any of the methods described herein), instead ofbeing formed within the polymer layer 105 over the first semiconductordevice 201 and the second semiconductor device 301, are formed withinthe polymer layer 105 over the first region 403 of the encapsulant 401.By forming the marks 805 within the polymer layer 105 over the firstregion 403 of the encapsulant 401 and not over the first semiconductordevice 201 and the second semiconductor device 301, the deleteriouseffects of the laser beam pulses 804 will be primarily limited to theencapsulant 401 and away from the first semiconductor device 201 and thesecond semiconductor device 301. As such, the first semiconductor device201 and the second semiconductor device 301 may have a reduced instanceof defects caused by the laser beam pulses 804.

In an embodiment the marks 805 are formed over the first region 403 ofthe encapsulant 401 and do not extend beyond the first region 403 of theencapsulant 401. As such, in an embodiment in which the first region 403of the encapsulant 401 has the first width W₁ (as described above withrespect to FIG. 4 ), the marks 805 have a second width W₂ that is lessthan the first width W₁, such as by being between about 100 μm and about850 μm, such as about 450 μm, although any suitable dimensions mayalternatively be utilized.

By forming the marks 805 over the encapsulant 401 and without extendingover the first semiconductor device 201 or the second semiconductordevice 301, such that the marks 805 are over the fan out area, anydamage that may occur because of an ill-controlled kerf depth during themarking process 801 may be mitigated. Additionally, any backside inducedheat spot effects or other damage may be reduced or eliminated. All suchimprovements help to increase the yield and efficiency of themanufactured devices.

FIG. 13 illustrates another embodiment which uses a wobble markingprocess 1300 to form the first line 807, and which may or may not beused with an overlap count greater than one or two. In this embodiment,rather than using the laser beam pulses 804 that had the first diameterD₁ which is equal to the dot width W_(d) of the first line 807 (asdescribed above with respect to FIG. 8B), a series of wobble laser beampulses 1301 (only the first of which is illustrated in FIG. 13 forclarity) with a second diameter D₂ that may be similar to the firstdiameter D₁ are utilized to form an outline 1303 that extends from afirst side 1305 of the first line 807 to a second side 1308 of the firstline 807, wherein the outline 1303 will extend across the dot widthW_(d) to form the first line 807. In an embodiment the wobble laser beampulses 1301 have the second diameter D₂, which may be between about 20μm and about 120 μm, such as about 50 μm. Additionally, the wobble laserbeam pulses 1301 may have an energy density of between about 1.0×10⁻³J/mm² and about 5.0×10⁻² J/mm², such as about 1.5×10⁻² J/mm², and thepolymer layer 105 is exposed for a time period of between about 1.0×10⁻⁵sec and about 8.0×10⁻⁵ sec, such as about 2.8×10⁻⁵ sec.

In order to form the first line 807 using the wobble marking process1300, a scan trace path 1307 may initially be generated where the firstline 807 is desired to be formed. While the scan trace path 1307 is notphysically formed within the polymer layer 105, the scan trace path 1307may be used by the laser control machine to place a series of wobblescan laser beam pulse exposures (represented in FIG. 13 by the dashedcircles labeled 1309).

To begin the scan trace path 1307, the dot width W_(d) is identified,and a line representative of the first side 1305 of the first line 807and a line representative of the second side 1308 of the first line 807are identified. In an embodiment the dot width W_(d) of the first line807 in the wobble marking process 1300 is between about 200 μm and about80 μm, such as about 150 μm. However, any suitable length for the dotwidth W_(d) may be utilized.

Once the dot width W_(d) has been identified, and the first side 1305 ofthe first line 807 and the second side 1308 of the first line 807 havebeen identified, the scan trace path 1307 may be identified. In anembodiment a series of points 1313 (labeled in order from 1-38 in FIG.13 ) may be placed in relation to a center line 1311 (between the firstside 1305 and the second side 1308 of the first line 807), the firstside 1305, and the second side 1308 of the first line 807. The preciselocation of the series of points 1313 may be stored in, e.g., a computerreadable storage medium such as a hard drive or other memory device.Once the series of points 1313 have been placed, individual arcs of thescan trace path 1307 may be formed to extend in order (e.g., from point“1” to point “2” and from point “2” to point “3”) between the points andform the scan trace path 1307 in preparation for the wobble laser beampulses 1301.

Overall, the individual arcs of the scan trace path 1307 maycollectively form a circular path that “wobbles” through the center line1311 from the first side 1305 of the first line 807 to the second side1308 of the first line 807. In an embodiment the scan trace path 1307(after making at least a first full rotation) will, after crossing thecenter line 1311, cross itself at least once, if not more, before againcrossing the center line 1311. In a particular embodiment, theintersection of the scan trace path 1307 with the center line 1311 asthe scan trace path 1307 moves from point to point may be a crossingdistance D_(c) of between about 50 μm and about 200 μm, such as about100 μm.

However, while the scan trace path 1307 may maintain a relativelyconstant distance between intersections with the center line 1311, aconstant distance is not intended to be limiting upon the embodiments.Rather, the crossing distance D_(c) may be variable along the scan tracepath 1307, such that the scan trace path 1307 may have varying distancesof intersection along the first line 807. Any suitable length may beused for the crossing distance D_(c) at any point along the scan tracepath 1307.

Once the scan trace path 1313 has been determined, the series of wobblelaser beam pulses 1301 may be used to form the series of wobble laserbeam pulse exposures 1309 (only a small number of which are illustratedin FIG. 13 ) along the scan trace path 1307, with individual ones of theseries of wobble laser beam pulse exposures corresponding with arespective one of the points (e.g., point “1,” point “2,” point “3,”etc.) as the exposures follow the marking trajectory along the labels#1, #2, #3, etc. In an embodiment the wobble laser beam pulses exposures1309 are formed at least partially overlapping each other in order toform the outline 1303 for the first line 807. For example, the secondwobble laser beam pulse exposure 1309 ₂ (at point “2”) may be offsetfrom the first wobble laser beam pulse exposure 1309 ₁ (at point “1”) byan offset of between about 5 μm and about 100 μm, such as about 50 μm.However, any suitable offset between the second wobble laser beam pulseexposure 1309 ₂ and the first wobble laser beam pulse exposure 1309 ₁may be used.

The series of wobble laser beam pulses 1301 is used to form the seriesof wobble laser beam pulse exposures 1309 along the scan trace path1307. As the series of wobble laser beam pulse exposures 1309 are formedthe outline 1303 will create the first line 807. By continuing the scantrace path 1307 and the formation of the wobble laser beam pulseexposures 1309 along the scan trace path 1307, the first line 807 may bemade in any desired length or shape.

Additionally, once the first line 807 is formed, it may be combined withother lines to form any desired characters. However, by forming thefirst line 807 using the wobble laser beam pulse exposures 1309, theoverall amount of material from the polymer layer 105 that is removed isreduced from within the first line 807. As such, fewer defects may becaused.

FIG. 14 illustrates a mark 805 formed using the first line 807 formedwith the wobble marking process 1300 (see FIG. 13 ). As illustrated, theoutline 1303 formed using the wobble marking process 1300 can be used toform characters, such as the letter “T”, “S”, “M”, and “C.” However, byusing the wobble laser beam pulses 1301, the letters are not solid butare, rather, outlined using the wobble laser beam pulse exposures 1309(not individually illustrated in FIG. 14 ), and a smaller portion of thepolymer layer 105 is removed for each line (e.g., the first line 807).Such a reduction helps to mitigate or eliminate defects caused by thelaser marking process.

Additionally, if desired, the first line 807 formed using the wobblemarking process 1300 may be used by itself or else combined with theother processes described above with respect to FIGS. 8A-12 . Forexample, the wobble marking process 1300 may be used to make lines thatare utilized in the cross-free characters as described above, or elsemay be used to make line that intersect with a reduced overlap count.Additionally, lines formed using the wobble marking process 1300 may beformed over the first region 403 of the encapsulant 401 withoutextending over the first semiconductor device 201 and the secondsemiconductor device 301. All suitable combinations of the processesdescribed herein are fully intended to be included within the scope ofthe embodiments.

FIG. 15 illustrates that, once the marks 805 have been formed within thepolymer layer 105, the structure may be bonded to a second package toform a first integrated fan out package-on-package (InFO-POP) structure1600 (see FIG. 16 ). FIG. 15 illustrates a bonding of backside ball pads1501 to a first package 1500. In an embodiment the backside ball pads1501 may be used to protect the exposed vias 111 and comprise aconductive material such as solder paste or an oxygen solder protection(OSP), although any suitable material may alternatively be utilized. Inan embodiment the backside ball pads 1501 may be applied using astencil, although any suitable method of application may alternativelybe utilized, and then reflowed in order to form a bump shape.

The first package 1500 may comprise a third substrate 1503, a thirdsemiconductor device 1505, a fourth semiconductor device 1507 (bonded tothe third semiconductor device 1505), third contact pads 1509, a secondencapsulant 1511, and fourth external connections 1513. In an embodimentthe third substrate 1503 may be, e.g., a packaging substrate comprisinginternal interconnects (e.g., through substrate vias 1515) to connectthe third semiconductor device 1505 and the fourth semiconductor device1507 to the backside ball pads 1501.

Alternatively, the third substrate 1503 may be an interposer used as anintermediate substrate to connect the third semiconductor device 1505and the fourth semiconductor device 1507 to the backside ball pads 1501.In this embodiment the third substrate 1503 may be, e.g., a siliconsubstrate, doped or undoped, or an active layer of asilicon-on-insulator (SOI) substrate. However, the third substrate 1503may alternatively be a glass substrate, a ceramic substrate, a polymersubstrate, or any other substrate that may provide a suitable protectionand/or interconnection functionality. These and any other suitablematerials may alternatively be used for the third substrate 1503.

The third semiconductor device 1505 may be a semiconductor devicedesigned for an intended purpose such as being a logic die, a centralprocessing unit (CPU) die, a memory die (e.g., a DRAM die), combinationsof these, or the like. In an embodiment the third semiconductor device1505 comprises integrated circuit devices, such as transistors,capacitors, inductors, resistors, first metallization layers (notshown), and the like, therein, as desired for a particularfunctionality. In an embodiment the third semiconductor device 1505 isdesigned and manufactured to work in conjunction with or concurrentlywith the first semiconductor device 201.

The fourth semiconductor device 1507 may be similar to the thirdsemiconductor device 1505. For example, the fourth semiconductor device1507 may be a semiconductor device designed for an intended purpose(e.g., a DRAM die) and comprising integrated circuit devices for adesired functionality. In an embodiment the fourth semiconductor device1507 is designed to work in conjunction with or concurrently with thefirst semiconductor device 201 and/or the third semiconductor device1505.

The fourth semiconductor device 1507 may be bonded to the thirdsemiconductor device 1505. In an embodiment the fourth semiconductordevice 1507 is only physically bonded with the third semiconductordevice 1505, such as by using an adhesive. In this embodiment the fourthsemiconductor device 1507 and the third semiconductor device 1505 may beelectrically connected to the third substrate 1503 using, e.g., wirebonds 1517, although any suitable electrical bonding may bealternatively be utilized.

Alternatively, the fourth semiconductor device 1507 may be bonded to thethird semiconductor device 1505 both physically and electrically. Inthis embodiment the fourth semiconductor device 1507 may comprise fourthexternal connections (not separately illustrated in FIG. 15 ) thatconnect with fifth external connection (also not separately illustratedin FIG. 15 ) on the third semiconductor device 1505 in order tointerconnect the fourth semiconductor device 1507 with the thirdsemiconductor device 1505.

The third contact pads 1509 may be formed on the third substrate 1503 toform electrical connections between the third semiconductor device 1505and, e.g., the fourth external connections 1513. In an embodiment thethird contact pads 1509 may be formed over and in electrical contactwith electrical routing (such as through substrate vias 1515) within thethird substrate 1503. The third contact pads 1509 may comprise aluminum,but other materials, such as copper, may alternatively be used. Thethird contact pads 1509 may be formed using a deposition process, suchas sputtering, to form a layer of material (not shown) and portions ofthe layer of material may then be removed through a suitable process(such as photolithographic masking and etching) to form the thirdcontact pads 1509. However, any other suitable process may be utilizedto form the third contact pads 1509.

The second encapsulant 1511 may be used to encapsulate and protect thethird semiconductor device 1505, the fourth semiconductor device 1507,and the third substrate 1503. In an embodiment the second encapsulant1511 may be a molding compound and may be placed using a molding device(not illustrated in FIG. 15 ). For example, the third substrate 1503,the third semiconductor device 1505, and the fourth semiconductor device1507 may be placed within a cavity of the molding device, and the cavitymay be hermetically sealed. The second encapsulant 1511 may be placedwithin the cavity either before the cavity is hermetically sealed orelse may be injected into the cavity through an injection port. In anembodiment the second encapsulant 1511 may be a molding compound resinsuch as polyimide, PPS, PEEK, PES, a heat resistant crystal resin,combinations of these, or the like.

Once the second encapsulant 1511 has been placed into the cavity suchthat the second encapsulant 1511 encapsulates the region around thethird substrate 1503, the third semiconductor device 1505, and thefourth semiconductor device 1507, the second encapsulant 1511 may becured in order to harden the second encapsulant 1511 for optimumprotection. While the exact curing process is dependent at least in parton the particular material chosen for the second encapsulant 1511, in anembodiment in which molding compound is chosen as the second encapsulant1511, the curing could occur through a process such as heating thesecond encapsulant 1511 to between about 100° C. and about 130° C., forabout 60 sec to about 3000 sec. Additionally, initiators and/orcatalysts may be included within the second encapsulant 1511 to bettercontrol the curing process.

However, as one having ordinary skill in the art will recognize, thecuring process described above is merely an exemplary process and is notmeant to limit the current embodiments. Other curing processes, such asirradiation or even allowing the second encapsulant 1511 to harden atambient temperature, may alternatively be used. Any suitable curingprocess may be used, and all such processes are fully intended to beincluded within the scope of the embodiments discussed herein.

In an embodiment the fourth external connections 1513 may be formed toprovide an external connection between the third substrate 1503 and,e.g., the backside ball pads 1501. The fourth external connections 1513may be contact bumps such as microbumps or controlled collapse chipconnection (C4) bumps and may comprise a material such as tin, or othersuitable materials, such as silver or copper. In an embodiment in whichthe fourth external connections 1513 are tin solder bumps, the fourthexternal connections 1513 may be formed by initially forming a layer oftin through any suitable method such as evaporation, electroplating,printing, solder transfer, ball placement, etc. Once a layer of tin hasbeen formed on the structure, a reflow is performed in order to shapethe material into the desired bump shape.

Once the fourth external connections 1513 have been formed, the fourthexternal connections 1513 are aligned with and placed into physicalcontact with the backside ball pads 1501, and a bonding is performed.For example, in an embodiment in which the fourth external connections1513 are solder bumps, the bonding process may comprise a reflow processwhereby the temperature of the fourth external connections 1513 israised to a point where the fourth external connections 1513 willliquefy and flow, thereby bonding the first package 1500 to the backsideball pads 1501 once the fourth external connections 1513 resolidifies.

FIG. 15 additionally illustrates the bonding of a second package 1519 tothe backside ball pads 1501. In an embodiment the second package 1519may be similar to the first package 1500, and may be bonded to thebackside ball pads 1501 utilizing similar processes. However, the secondpackage 1519 may also be different from the first package 1500.

FIG. 16 illustrates a debonding of the third external connectors 505from the ring structure 601 and a singulation of the structure to formthe first integrated fan out package-on-package (InFO-POP) structure1600. In an embodiment the third external connectors 505 may be debondedfrom the ring structure 601 by initially bonding the first package 1500and the second package 1519 to a second ring structure using, e.g., asecond ultraviolet tape. Once bonded, the ultraviolet tape 603 may beirradiated with ultraviolet radiation and, once the ultraviolet tape 603has lost its adhesiveness, the third external connectors 505 may bephysically separated from the ring structure 601.

Once debonded, a singulation of the structure to form the first InFO-POPstructure 1600 is performed. In an embodiment the singulation may beperformed by using a saw blade (not shown) to slice through theencapsulant 401 and the polymer layer 105 between the vias 111, therebyseparating one section from another to form the first InFO-POP structure1600 with the first semiconductor device 201. However, as one ofordinary skill in the art will recognize, utilizing a saw blade tosingulate the first InFO-POP structure 1600 is merely one illustrativeembodiment and is not intended to be limiting. Alternative methods forsingulating the first InFO-POP structure 1600, such as utilizing one ormore etches to separate the first InFO-POP structure 1600, mayalternatively be utilized. These methods and any other suitable methodsmay alternatively be utilized to singulate the first InFO-POP structure1600.

In accordance with an embodiment, a semiconductor device comprising asemiconductor device with an encapsulant and a via extending through theencapsulant and laterally separated from the semiconductor device isprovided. A protective layer is over the encapsulant and the via. Amarking is within the protective layer, the marking comprising across-free character.

In accordance with another embodiment, a semiconductor device comprisinga semiconductor die and a conductive via laterally separated from thesemiconductor die is provided. An encapsulant is located between thesemiconductor die and the conductive via, and a protective material overthe encapsulant. A marking character is within the protective material,wherein the marking character has an overlap count of less than two.

In accordance with yet another embodiment, a semiconductor devicecomprising a semiconductor die laterally separated from a conductive viaand an encapsulant encapsulating both the semiconductor die and theconductive via is provided. A layer of material is over thesemiconductor die, the encapsulant, and the conductive via. A characteris marked into the layer of material, wherein the character comprises aplurality of laser pulse exposure regions, each of the laser pulseexposure regions having a diameter of less than about 100 μm and each ofwhich is aligned along a circular trace path, the circular trace pathoutlining the character.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A semiconductor device comprising: a firstsemiconductor device separated from a through via by an encapsulant,wherein a protective layer is located over the first semiconductordevice and wherein the through via has multiple surfaces planar with thefirst semiconductor device; and a circular path traced across theprotective layer by a plurality of circular indentations, wherein eachof the plurality of circular indentations has a diameter of less thanabout 100 μm.
 2. The semiconductor device of claim 1, wherein thecircular path has a crossing distance of between about 50 μm and about200 μm.
 3. The semiconductor device of claim 2, wherein the circularpath has a crossing distance of between about 50 μm and about 100 μm. 4.The semiconductor device of claim 1, wherein the circular path has avariable crossing distance.
 5. The semiconductor device of claim 1,wherein the plurality of circular indentations at least partiallyoverlap each other.
 6. The semiconductor device of claim 1, wherein thecircular path forms a line, the line having a dot width of between about80 μm and about 200 μm.
 7. The semiconductor device of claim 6, whereinthe line has an overlap count greater than two.
 8. A semiconductordevice comprising: a protective layer located over a first semiconductordevice, the first semiconductor device being encapsulated by anencapsulant; through vias extending through the encapsulant, wherein atleast one of the through vias has a straight sidewall that extends froma first side of the encapsulant to a second side of the encapsulantopposite the first side; and a plurality of circular indentationsextending into the protective layer and having a diameter of less thanabout 100 μm, the plurality of circular indentations located along acircular path traced across the protective layer by the plurality ofcircular indentations.
 9. The semiconductor device of claim 8, whereinthe circular path forms a line.
 10. The semiconductor device of claim 9,wherein the circular path has a crossing distance within the line ofbetween about 50 μm and about 200 μm.
 11. The semiconductor device ofclaim 10, wherein the circular path has a crossing distance within theline of between about 50 μm and about 100 μm.
 12. The semiconductordevice of claim 9, wherein the line has a variable crossing distance.13. The semiconductor device of claim 9, wherein the line has a dotwidth of between about 8 μm and about 150 μm.
 14. The semiconductordevice of claim 8, wherein the circular indentations have a diameter ofbetween about 20 μm and about 50 μm.
 15. A semiconductor devicecomprising: an encapsulant encapsulating a first semiconductor die and athrough via; and a protective layer overlying at least the firstsemiconductor die and the encapsulant, wherein a top surface of theprotective layer comprises multiple overlapping indentations, each oneof the multiple overlapping indentations being circular in shape andhaving a diameter of no greater than about 100 μm, the multipleoverlapping indentations forming a curved line, the curved line having adot width that is greater than the diameter.
 16. The semiconductordevice of claim 15, further comprising a redistribution layer locatedacross the encapsulant from the protective layer.
 17. The semiconductordevice of claim 15, wherein the multiple overlapping indentations wobblethrough a centerline of a line.
 18. The semiconductor device of claim17, wherein the line has a dot width between about 80 μm and about 200μm.
 19. The semiconductor device of claim 15, wherein each of themultiple overlapping indentations has a diameter of between about 20 μmand about 50 μm.
 20. The semiconductor device of claim 15, wherein thethrough via is recessed within the encapsulant.